1. Field of the Invention
The present invention relates to a case for packaging a wrap film, an aluminum foil, paper or the like which is rolled on a cylindrical core.
2. Related Background Art
Various conventional wrap film cases are known. Generally, each case comprises a case body for storing a rolled wrap film and a lid integrally formed with the case body, as described in Japanese Patent Laid-Open Nos. 63-55043 and 64-9151. In use of such a conventional case, the following operations are generally performed. A user opens the lid upward and pulls the wrap film from the case body by a desired length. The wrap film is then cut with a cutter mounted on the bottom wall of the case body or the front wall of the lid.
However, in a general conventional wrap film case, as a case body is simply covered with a lid, the lid may float to externally expose the opening portion of the case body, depending on a way of handling the case. To expose the opening portion of the case body is not preferable from the sanitary viewpoint or may cause the wrap film to drop from the case body. In addition, while the lid is kept floating, the free end of the wrap film may be rewound into the case body to make it difficult to pull the wrap film in re-use.
To solve the above problem, there is proposed a conventional packaging case having a lid floating preventive function, as described in Japanese Utility Model Laid-Open No. 4-89732. This case has flap pieces extending downward on the outer sides of top edge portions of right and left side walls of case body, and stepped portions projecting inward on the inner surfaces of right and left side walls of a lid. When the case body is capped by the lid, the flap pieces engage with the stepped portions to prevent the lid from floating.
In the case described in Japanese Utility Model Laid-Open No. 4-89732, desired effects cannot be obtained because the flap pieces and the stepped portion are respectively formed on the case body and the lid without devices. To smoothly open/close the lid, the flap pieces must be movable inward in the case body during the opening/closing operation of the lid. In the conventional case described above, however, the flap pieces can rarely be moved inward in the case body because a space between each end portion of a wrap film core stored inside the case body and the corresponding side wall which supports the corresponding flap piece is very small or absent. For this reason, after the lid is closed and the flap pieces are engaged with the stepped portions, respectively, it is difficult to separate the flap pieces from the corresponding stepped portions. Therefore, the lid cannot be easily opened, resulting in inconvenience. Specially, it is important that the lid can be opened, because there are many instances where, in a home, a female user handles the lid by one hand.
When products, i.e., cases each storing a wrap film are stocked in a whorehouse or the like, a plurality of parallelepiped cases are stored in a cardboard box such that their longitudinal direction is aligned with the vertical direction, and a plurality (e.g., 10) of such cardboard boxes are generally stacked on each other and stocked. In this instance, the products in a lower cardboard box receive a large longitudinal load for a long period of time. In the conventional case described above, the right and left side walls of the case body are supported by the wrap film core. For this reason; when large inward forces act on the side walls during stocking, the flap pieces cannot move inward, and the flap pieces are excessively pressed against the side walls of the case body. As a result, an angle formed between each flap piece and the corresponding side wall often becomes very small. In this manner, when the flap pieces are excessively bent, the flap pieces cannot be smoothly swung. Therefore, it may be difficult to omen the lid.
To solve these problems there may be proposed a means for setting a distance between the right and left side walls of the case body to be much larger than the overall length of the wrap film core, thereby forming a space between each side wall and the corresponding core end portion to allow inward movement of each flap piece. When this space is formed, however, another problem such as collapse of the side walls during longitudinally stocking is posed.